BMW's new mainstream electric sedan is starting to take shape. With development well underway, the automaker has released enough information to make clear that it's taking Tesla's latest offerings very seriously. 

How seriously? Try 530 horsepower and 300 miles of total range for the top-trim model, and an 80-kilowatt-hour battery pack based on BMW's new 5th-generation architecture, which is lighter and more compact than the batteries being used in its current generation of EVs and PHEVs. According to BMW, the fifth-generation tech essentially puts the motor, transmission, and power electronics all under a single housing and moves to electric motors that will no longer require rare-earth materials.

The i4 will be capable of 150-kilowatt DC fast charging, which BMW says can deliver 80 percent of its total charge in just 35 minutes. On the U.S.'s EPA cycle, the longest-range variant of the i4 should be able to go at least 300 miles on a single charge.

BMW already has i4 prototypes testing in the real world, though it is unlikely that BMW's mules are wearing the i4's final production bodywork. BMW has already said that the i4's exterior will be based on the i Vision Dynamics concept from the 2017 Frankfurt Motor Show. 

The i4 will be part of the next 4-Series family. It is expected to be closely related to the 4-Series Gran Coupe but may sit higher to allow space for batteries above the axles (rather than just between them). The platform will be shared with ICE variants of the new 4-Series and 3-Series, as BMW continues to blur the lines between its gasoline-powered cars and dedicated EVs.

One thing is for certain: The BMW i4 will not be the concept that was pitched to the world at the 2012 Los Angeles auto show. That relic of BMW's "i" brand was to be a coupe slotted between the existing i3 (to be discontinued without a replacement) and the i8 sports car. As BMW accelerates its efforts to electrify its mainstream models, "i" brand vehicles will cease to be their own distinct lineup. 

Look for the i4 to arrive in 2020, likely as a 2021 model.